BB fails to work

After renewing my mothers cell phone contract on 11/04/2015 we are now having issues with the phone and using the internet or social media. I have tried to sort the problem out telephonically with the call centre which told me the problem would take between 24 to 48 hours to repair. To my dismay the problem has still not been rectified. My mother has now gone to the Vodacom repair shop to try get the problem sorted out and was told that the problem cannot be rectified and they cannot help her. Is the phone not under warranty? The Vodacom shop never even took the phone in to try repair it, they just sent my mother on her way after telling her that a lot of the BB9720's have this problem and there is nothing they can help her with. Where is the customer service? Surely the phone should be taken in for repairs or we should be issued with a new phone seen as this particular phone only worked properly for about a month and the contract was upgraded recently.